Apparatus for casting



(No Model.)

3 Slgeets8heet 2. H. G. UNDERWOOD. APPARATUS FOR CASTING.

Patented'f'eb. 5,1895.

ma NORM! was: on. PHGTD-LITHD, WkSHINGTON, D c.

(No Model.) 3 SheetsSheet 3.

H. G. UNDERWOOD. APPARATUS FOR UASTING.

No. 533,685. Patented Feb. 5, 1895.

34/ Inventor.-

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Urirno STATES ATENT rerun.

HERBERT G. UNDElRvVOOD, OF YONKERS, ASSIGNOR TO HERBERT H. FRANKLIN, OFSYRACUSE, NEIV YORK.

APPARATUS FOR CASTlNG.

3PEGIFICATION forming part of Letters Patent No. 533,685, dated February5, 1895.

Application filed May 8,1894. erial No.5l0,44.2. {No model.)

paratus for Casting; and I do hereby declare that the following is afull and exact description thereof, reference being bad to theaccompanyingdrawings, and to the letters of referonce marked thereon,making a part of this specification.

This inven tion relates to the moldin g of articles which should beturned out of the mold in a practically perfect condition in order thatthe manufacture maybe conducted econominally.

In another application for Letters Patent, filed August 8, 1893, andnumbered serially 484,448, there have been described and shown a certainmethod and an apparatus for accomplishing the general result referred toabove. The apparatus is found to work well in practice, particularlywhen using metals which have a comparatively low fusing point. In thepractical operation of the apparatus, however, it has been found thatcertain modifications and improvements can be employed with good eifect,particularly in working with metals which have a comparatively high fusing point. In working with the harder metals it is especiallydesirable that the mold itself should be brought as close as possible tothe body of molten material in the melting pot in order that the moltenmetal may not chill during its passage into the mold. For the samereason and also that no part of the apparatus may be clogged by chilledmetal it is desirable that the high temperature of all parts except themold should be maintained and that all of the molten metal which isseparated from the whole mass at each operation and is not forced intothe mold itself should be returned at once to the whole mass case havebeen devised to meet the several requirements above alluded to and as aresult it has become possible to produce successfully and economicallymolded articles of hard metal which require practically no finishingafter their removal from the molds.

Various features of improvement will be described in detail hereinafterand different forms of apparatus in which the improvements may beembodied will be described, but it will be observed that all the formsof apparatus shown embody such an arrangement of parts that the cylinderor its equivalent chamber and the plunger or piston, by means of whichthe portion of molten metal is forced into the mold, are so supported asto be submerged within the mass of molten material, that the portthrough which the molten metal is forced from the cylinder into the moldis so placed as to permit the metal not carried away with the mold todrop back beneath the surface of the mass of molten metal to bevirtually encompassed by the whole body thereof, and that the molditself is adapted to be held with its ingate practically in close andimmediate contact with the port through the wall of the cylinder.

In the drawings: Figure 1 is a partly sectional elevation of a furnaceand melting pot equipped with one form of the improved apparatus, themelting pot being broken out to show the means for forcing the metalinto the mold. Fig. 2 is a vertical, central section through thecylinder and plunger shown in Fig. 1. Fig. 3 is a vertical, centralsection through an apparatus of a slightly different form from thatshown in Fig. 1, the means for operating the plunger being broken off.Figs. 4. and 5 are vertical, central sections through other forms of theapparatus, the cylinder and plunger being horizontally disposed. Fig. 6is a bottom view of a mold and cut-0E which may be used. Fig. 7 isalongitudinal section of the mold and cut-0d shown in Fig. 6. Figs. 8 and9 are respectively a bottom View and a longitudinal section showinganother arrangement of the cut-off; and Figs. 10 and 11 are respectivelya top view and a longitudinal section showing still another arrangementof the cutoff. Fig. 12 is a detail view in section, illustrating amodified form of the cylinder or chamber and its plunger. Fig. 13 is apartial section on the line ww ofFig.12. Figs. 14 and 15 are similarviews showing a different arrangement of the cylinder or chamber andplunger, the line y-y of Fig. 1e indicating the plane of section of Fig.15.

Referring first to Figs. 1 and 2 it will be seen that a crucible ormelting pot A of an ordinary shape is supported within a furnace B. Asrepresented, the crucible or pot is supported by lugs c, c, on the underside of a plate 0 which covers or extends across the top of the pot A.The plate 0, whatever may be its position, is adapted to receive andsupport upon its upper surface the mold which is to be used and isprovided with an aperture or port 0 which registers and makes close contact with the ingate of the mold or with an opening through a platewhich may be considered as a part of the mold, as will be moreparticularly described hereinafter. To the under or inner side of theplate 0 is rigidly secured, so as to be practically in one piecetherewith, a chamber or cylinder D which has in its upper wall a port (1which registers with the port 0 in the plate 0.

It will be readily understood that the plate 0 and the cylinder D mightbe formed in one piece, it being merely essential that the port 0 d,shall be formed through the upper wall of the cylinder in such positionthat the mold may be held firmly with its ingate against said port andthat whatever may pass inward through such port shall fall within thecylinder.

As the cylinder itself is submerged in the molten material in the pot itwill be seen that such portion of the molten metal as is forced into themold at each operation has only a short distance to travel (the moldbeing separated from the pot only by the thickness of the plate 0) andthat Whatever metal maybe returned through or from the port 0 d fallsbelow the surface of themass of molten metal and is encompassed by thewhole mass, being therebyimmediately brought to the requiredtemperature. Moreover, as the cylinder D is submerged in the mass ofmolten metal the plate 0 is kept very hot and as a result the -metal isnot chilled on its way to the mold and the port 0 d is kept clear. Themold, however, is protected by the plateG from the intense heat of themolten mass, and being kept in contact therewith only for a short timeat intervals, may be kept at a suitably low temperature.

An ordinary solid plunger, fitting freely inside of the cylinder D,might be used to force the molten metal outward through the port 0 d,but certain advantages are secured by using what may be termed anoutside plunger or bucket E, the same being a cylinder with closedbottom and working freely on the outside of the cylinder D. Movement ofthe cylinder or of the plunger may be produced by any suitable means.

As represented, the plunger may be carried by rods f,f, from across-head F, the latter being connected by a link f to an operatinglever G. The upper edge of the plunger or bucket E is cut away somewhat,as at e, to permit the bucket to fill without being dropped wholly belowthe end of the cylinder D.

As the bucket is filled at every operation the extent of movementnecessary to be imparted to the cross-head F to fill a certain mold canbe more exactly determined than would be possible with an inside plungerwhen the level of the molten metal in the pot changes. Moreover, byreason of the reasonably large inside diameter of the bucket E a smallermovement thereof is required to force a given quantity of metal throughthe port 0 d.

In some cases, Where a particularly high temperature is required, it isdesirable that the plate which supports the cylinder D shall be sunkbelow the level of the rim of the crucible, as represented at O in Fig.3, and, in lesser degree, in Figs. 4 and 5. The upper end of thecylinder D and the walls of the port 0, being surrounded by the heat ofthe crucible, are thus maintained at a high tom peratur'e.

In Fig. at are represented a furnace B, and

melting pot A which are covered or bridged as before by a plate 0. Thelatter is adapted to receive and support the mold in close contact withits upper face and is provided with a port 0 which registers with a portd in the upper wall of the cylinder D, which is supported in ahorizontal position. The cylinder D is adapted to be submerged in themolten metal and, as in the construction shown in Fig. 1, the materialwhich drops back through the port 0 d, is encompassed by the mass ofmolten metal in the pot. The outside plunger or bucket E has an arm Fwhich is secured to a slide rod G to be operated by any suitable means.In this View, Fig. 4;, the cylinder D is shown as integral with thebridge plate 0'.

The construction represented in Fig. 5 is substantially the same as thatshown in Fig. 4 except that a solid plunger E working freely inside ofthe cylinder D replaces the outside plunger or bucket. After a mold hasbeen filled it might be removed from the filling devices withoutattempting to shear off the sprue or the sprue might be sheared off bysliding the mold upon the plate or bridge 0 or C. In order, however,that better results may be secured and particularly that the sprue maybe sheared off readily while the metal in the mold is still underpressure, it is preferable to employ an independent cut-off which isatlinear movementacross the opening in the body of the mold, In theconstruction shown in Figs. 6 and 7 the main part H of the mold isrepresented as having pins h, h, which may be engaged with eyes on thesupporting plate for convenience in holding the mold firmly over theport 0 d. To the part II is hinged the part I through which the ingate'11 is formed. The cut-0d K in this case is pivoted upon the part I sothat it may slide with a curvilinear movement across the opening i andis a flat plate so that it may make close contact both with the part Ion the one side and with the plate G or C on the other. It is providedwith an aperture which is in effect the ingate of the mold and when themold is being filled is so placed as to register with the opening 2'. Assoon as the filling is completed and while the metal in the mold isstill under pressure from the filling devices the cut-cit is moved toshear off the metal across the opening 11, leaving the correspondingside of the molded article smooth. The small portion of metal whichremains in the aperture ll; will fall out of itself when the mold israised.

In the construction shown in Figs. Sand 9 the plate I, which forms apart of the mold and is provided with the aperture '1', has ways 1;, i,in which the cut-off plate K, having the aperture is, may slide to andfro. An operating lever L may be mounted upon the plate I and beconnected to the cut-off by a link Z.

In Figs. 10 and 11 the plate I which as before forms a part of the moldand has an aperture i, is represented as having a guideway i in whichslides a bar or plate K being operated by a lever L. The bar or plate Kis not formed with an aperture but its end, which when the mold is beingfilled forms a part of one side of the ingate,shears the metal in itsmovement across the opening 2'.

As shown in Figsl, 2, 3, 4: and 5 the chamber D or D is cylindrical inform, but it is obvious that this part of the apparatus might have someform other than cylindrical and the term cylinder, as employed herein,is used with that understanding. Thus, in Figs. 12 and 13 the cylinderor chamber D is shown as substantially triangular with an open sidewhile the plunger is in the form of a plate valve E which has a bearingat the bottom and fits freely between the parallel walls of the chamberso that it may be moved to force the molten metal out through the port 0in its upper wall.- The plunger may be operated by a rod G connected toan arm F which is rigidly secured to the plunger, the rod G workingthrough a hole in the plate 0. In Figs. 14: and 15 the chamber orcylinder D is shown as reversed, the plate E being supported by a shaftF in a suitable bearing at the top of the chamber and operated by alever G which is secured to the shaft F.

The several forms of cut-offs and of devices for forcing the moltenmetal into the mold shown in the drawings and described above arepractical and efiicieut. They are chosen merely to illustrate theimprovements, however, and it will be understood that it is not intendedto restrict the invention to the specific forms shown. Many other formswill be readily suggested by the special requirements of diderent cases.W'hatever may be the special form of the cut-off it permits the mold tobe brought very close to the body of molten metal, closes the openinginto the mold while the metal is still under pressure, shears off thesprue neatly and quickly whether the metal be hard or fluid, and in thelatter case italso chills the metal between the casting and the ingateand thereby insures a better finish for the corresponding side of thecasting.

It will be observed that in the constructions shown in Figs. 10 and 11the cut-off bar or plate forms at least a part of one side of the molditself, or, in other words, that a part of the mold is made movable toshear the sprue.

I claim as my invention 1. In an apparatus for casting, a pot orcrucible for the molten metal, a support to which the same is attached,a chamber within the pot or crucible also attached to said supportsubmerged in the molten metal and having a port in its upper wall, amold also resting on said support and having its ingate just above theport of the chamber with means for fore ing the molten metal from thechamber into the mold; substantially as described.

2. The combination of a pot for molten metal, a cylinder supportedwithin said pot to be submerged in the molten metal therein and having aport through its upper wall, a plunger and means to operate the same toforce molten metal out through said port and a stationary support uponwhich a mold may be held with its ingate adjacent thereto and forming aclose joint with said port, whereby the molten metal has the shortestpossible.

distance to move and is therefore not likely to be chilled in itspassage into the mold, and whereby the metal not carried away as themold is removed may fall back from the port into the cylinder and withinthe body of molten metal in the pot.

3. The combination of a'pot for molten metal, a stationary bridge plateacross the top of said pot and having an aperture, a cylinder suspendedbelow said plate to be submerged in the molten metal in said pot andhaving an aperture registering with the aperture in said plate to form adischarge port, a plunger and means to operate the same to force moltenmetal out through said port, said bridge plate forming a support uponwhich a mold may be held with its ingate forming a close joint with saidport.

4. The combination of a pot for molten metal, a bridge plate across thetop of said pot and having an aperture, a cylinder suspendedbelow saidplate to be submerged in the molten metal in said pot and having anaperture registering with the aperture in said plate to form a dischargeport, aplunger and means whereby relative movement of said cylinder andplunger may be produced to force-molten metal out through said port,said bridgeplate being depressed below the level of the top of the potto form a support upon which a mold may be held with its ingate forminga close joint with said port.

5. The combination of a pot for molten metal, a cylinder supportedwithin said pot to be submerged in the molten metal therein and having aport through its upper wall, a bucket plunger fitting freely over theoutside of said cylinder, means to cause a relative movement of thecylinder and plunger to force molten metal out through said port, and asupport upon which a mold may be held with its ingate in communicationwith said port.

6. Thecombination of a pot for molten metal having an outlet port, meansto force the molten metal out through said port, a mold having anaperture, a support upon which said mold may be held with its aperturein communication with said port, and a cut-off plate interposed betweensaid mold and supported and adapted to be moved across the aperture insaid mold while the latter is in position upon said support.

7. The combination of a pot for molten metal having an outlet port,means to force the molten metal out through said'port, a mold having anaperture, a support upon which said mold may be held with its aper turein communication with said port, and a cut-01f plate interposed betweensaid mold and said support and having an aperture to register with theaperture in said mold, said plate being movable across the aperture insaid mold.

8. The combination of a pot for molten metal having an outlet port,means to force the molten metal out through said port, a mold having anaperture, a support upon which said mold may be held with its aperturein communication with said port, and a cut-oft plate movably attached tothe bottom chamber attached to said support extending below the samesuch a distance as to be submerged in the pot of molten metal, a moldabove said chamber and resting on said support, with suitable ports inthe chamber and mold registering with one another, and means for forcingthe material from the submerged chamber into the mold; substantially asdescribed.

10. In an apparatusfor casting, the combination with the pot or cruciblefor the moiten metal, a cylinder supported within the pot, to besubmerged in the molten metal therein and having a port through itsupper wall, and a hollow plunger with means for moving the same inrelation to the cylinder to force molten metal out through said port anda mold with its ingate adjacent to and in close communication with saidport; substantially as described,

11. In an apparatus for casting a pot or crucible for the molten metalwith means for supporting it within the furnace, a chamber within thepot or crucible with a stationary support to which it is attached, saidchamber being submerged in the molten metal and having a port in itsupper wall, and a mold placed above the chamber, and having an ingateregistering with the port of the chamber, and in close communicationtherewith, with means for forcing the material from the submergedchamberinto the mold; substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

HERBERT G. UNDERNOOD.

Witnesses:

FRANCIS B. GILL, GILES I-I. STILWELL.

